The present invention relates to a nanoprint apparatus for making a fine structure on a substrate with the use of a mold having a heating and pressing mechanism, and also to a method of making a fine structure.
These years, microfabrication for semiconductor integrated circuits has been progressed and the degree of integration of semiconductor integrated circuits has been enhanced, and accordingly, the accuracy of photolithography apparatuses for the lithography of pattern transcription which carries out the microfabrication. The lithography has approached the limits of its ability since features in a pattern to be fabricated become extremely fine up to wavelengths of light sources for optical exposure. Thus, in order to fabricate a fine structure having higher integration with a high degree of accuracy, it has been attempted to use an electron beam drawing apparatus which is one kinds of charged particle beam apparatuses, instead of the lithography apparatuses.
The formation of a pattern with the use of an electron beam utilizes a method of drawing a mask pattern, instead of a batch image-transcription for fabricating a pattern with the use of a light source of i-ray beam, excimer laser or the like, the larger the number of patterns to be drawn, the longer the exposure time, there is caused a such a deficiency that the longer the exposure time, a relative long time is required for the fabrication of a pattern. Thus, should the degree of integration be leaped up to 256 Mega, 1 Giga or 4 Giga, a problem of remarkably lowering throughput would be caused. Thus, for the purpose of speed-up of the electron beam drawing apparatuses, there has been tried the development of a batch pattern irradiating process in which an electron beam is irradiated to a combination of masks of various configurations in a batch in order to obtain an electron beam having a complicated configuration. As a result, should the degree of fineness of patterns be heightened, the electron beam drawing apparatus would be large-sized while a mechanism for controlling the position of a mask with a relatively high degree of accuracy would be required. Thus, there has been caused such a problem of increasing the cost of the apparatus.
For example, U.S. Pat. Nos. 5,256,962, 5,772,905 and Appl. Physics, Letter Vol, 67, P3314(1955), authed by S. Y. Chou et al, disclose a technology for fabricating a fine pattern at a low cost. In this technology, a mold having concavities and convexities defining a predetermined pattern the same as that to be formed on a substrate to be image-transferred is pressed against a resist film layer formed on the surface of a substrate. In particular, a nanoprint technology disclosed in the U.S. Pat. No. 5,772,905 or Appl., Physics, Letter utilizes a mold formed of a silicon wafer for fabricating a fine structure of not greater than 25 nanometer through image-transcription.
However, there has been desired a technology of transcription a fine pattern with a high degree of accuracy with the use of an imprint process capable of fabricating a fine pattern.
After various studies, the applicants have found such a fact that should heating and pressing of a substrate and a mold be not uniform, no precise imager transcription could be carried out, and have been devised the present invention.